Hou Sheng-Mou, Lin Jinn
Department of Orthopedic Surgery, National Taiwan University Hospital, Taipei 100, Taiwan.
J Formos Med Assoc. 2004 Nov;103(11):836-43.
The use of locked nailing for the treatment of humeral nonunions is threatened by the potential of initial instability which may result in residual fracture gap and motion and is detrimental to fracture healing. This study investigated the biomechanical and clinical effects of adding interfragmentary wiring to reduce the initial instability in the treatment of humeral nonunion.
The biomechanical study compared the mechanical properties of 3 fixation methods: locked nail alone, with staple, and with interfragmentary wiring. Composite humeri were transected to simulate nonunion and were retrograde nailed. Nail-bone constructs were examined by non-destructive bending tests and destructive torsional tests. The initial instability, fixation stiffness and strength were measured and compared. The clinical study compared 21 nonunions treated by locked nailing alone and 30 nonunions treated by locked nailing with interfragmentary wiring. The indication for wiring was persistent nonunion gap or motion during operation. The union rate, time to union, functional recovery of the adjacent joints and the time for functional recovery were compared between the treatment groups.
Biomechanically, in both bending and torsional tests, locked nailing with a staple or wiring resulted in significantly less initial instability than locked nailing alone. Test results for bending stiffness, torsional stiffness, or torsional strength did not differ significantly among the 3 fixation methods. In the clinical study, interfragmentary wiring had the advantage of providing tight nonunion compression, which was beneficial for nonunion healing and promoted early postoperative exercise. Patients treated with locked nailing with interfragmentary wiring had significantly shorter time to union and faster shoulder functional recovery (p < 0.05).
Adding interfragmentary wiring was an effective and safe procedure in humeral nonunions treated with locked nailing.
带锁髓内钉治疗肱骨骨不连时，初始稳定性欠佳可能导致骨折间隙残留及断端活动，进而影响骨折愈合。本研究旨在探讨采用骨折块间钢丝固定以降低初始不稳定性在肱骨骨不连治疗中的生物力学及临床效果。
生物力学研究对比了3种固定方法的力学性能：单纯带锁髓内钉、联合骑缝钉及联合骨折块间钢丝固定。将合成肱骨截断模拟骨不连，行逆行髓内钉固定。通过无损弯曲试验及破坏扭转试验检测钉-骨结构。测量并比较初始稳定性、固定刚度及强度。临床研究对比了21例单纯带锁髓内钉治疗的骨不连与30例带锁髓内钉联合骨折块间钢丝固定治疗的骨不连。钢丝固定的指征为术中持续存在骨不连间隙或断端活动。比较治疗组间的骨愈合率、愈合时间、相邻关节功能恢复情况及功能恢复时间。
生物力学方面，在弯曲及扭转试验中，联合骑缝钉或钢丝固定的带锁髓内钉初始稳定性均显著低于单纯带锁髓内钉。3种固定方法在弯曲刚度、扭转刚度或扭转强度的测试结果无显著差异。临床研究中，骨折块间钢丝固定具有紧密压缩骨不连的优势，有利于骨不连愈合并促进术后早期活动。带锁髓内钉联合骨折块间钢丝固定治疗的患者愈合时间显著缩短，肩关节功能恢复更快（p < 0.05）。
在带锁髓内钉治疗肱骨骨不连时增加骨折块间钢丝固定是一种有效且安全的方法。
